The United States natural gas demand is expanding but production is declining and due to that natural gas prices have risen sharply. One method of distributing this energy source is to gasify the coal to produce synthesis gas and then convert it to substitute natural gas via methanation. Current state of the art methanation uses a nickel catalyst which imposes certain operating limitations because of its susceptibility to deactivation by surface carbon and poisoning by surface sulfur.
MoS2 and other sulfur tolerant catalysts based on the transition elements find wide application in the processing of hydrocarbon feedstock's particularly in methanation if they possess sufficient high activity. At present nickel based catalysts are used in methanation because of their high activity, but they are extremely sensitive to deactivation by surface carbon, high temperature and poisoning by various sulfur compounds present in synthesis gas obtained from coal gasification. Sulfur-tolerant MoS2 catalyst can overcome many of the restrictions associated with nickel catalyst. In addition, a recent economic study by Fluor compared sulfur-tolerant methanation with conventional methanation found a 3% reduction in the total plant investment and a 4.5% reduction in the cost of the substitute natural gas plant. The most active sulfur-tolerant catalyst found for methanation in the literature is a MoS2 catalyst initially developed by the Gas Research Institute.
There exists a need to develop a process to create a more active MoS2 catalyst than what is currently available which can be tested in a fixed bed unit and show a high activity for synthesis gas methanation.